Coronary calcium tests not always worthwhile: study

NEW YORK (Reuters Health) - Using CT scans of coronary arteries to help determine a person's chance of getting heart disease may be worth the costs and potential risks in men, but doesn't seem to be cost-effective in women.

That's according to a new study that used a computer simulation to compare the expense, as well as the benefits and side effects, of different ways to treat people thought to be at moderate risk for heart disease.

A CT scan of coronary calcium allows doctors to see how much build-up there is in the blood vessels leading to the heart. A lot of build-up raises a warning flag that a person is more likely to get heart disease, while little build-up means the risk of disease is low.

Being able to better define a patient's risk tells doctors the best way to treat them -- for example, whether they should be taking drugs to lower cholesterol and blood pressure.

"That's what the Holy Grail is here, to precisely (define) someone's risk," said Colonel Patrick O'Malley, of the Uniformed Services University in Bethesda, Maryland.

"You want to aggressively treat high-risk patients and withhold treatments for low-risk patients," explained O'Malley, who has studied coronary calcium screening but wasn't involved in the new research.

All the hypothetical patients considered in the computer analysis were assumed to have a moderate risk of heart disease based on traditional measurement tools, including cholesterol, blood pressure, gender and age. On average, they were older than 69.

Moderate, or intermediate, risk means a person has a 10 to 20 percent chance having a heart attack or other heart-related "event" in the next decade.

Researchers looked at four different scenarios in their model, considering for each the chances that patients would have a stroke or heart attack along with the costs of appointments, procedures and drugs and the possible risks and side effects associated with the treatments themselves.

Those scenarios included: treating patients without any special heart-related interventions, giving patients healthy lifestyle advice and putting those with high cholesterol or blood pressure on medication, having every patient take a cholesterol-lowering statin drug or using coronary calcium screening to better estimate heart risks and decide who needs extra treatment.

When all the calculations were done, coronary calcium screening was the most effective and also the most expensive option in men. Researchers calculated that about $49,000 would have to be spent on testing and associated treatment to get a man one extra year in excellent health.

In comparison, following current guidelines that recommend giving lifestyle advice to all moderate-risk women and drugs to those who need them would be more effective than coronary CT scans and cost a similar amount, the researchers reported in the Journal of the American College of Cardiology.

CT scans for coronary calcium can cost anywhere from $50 to $600, researchers said, and usually aren't covered by insurance.

"You want to know beforehand whether performing such a (test) is worth the risk and the cost," said Dr. Myriam Hunink, from Erasmus Medical Center in Rotterdam, The Netherlands, who worked on the study.

Those risks include extra radiation from CT scans and the chance of having an "incidental finding," something that wouldn't have caused a patient harm but requires more procedures and testing -- with possible side effects -- to check out.

"The bottom line is there's still a lot of uncertainty," she told Reuters Health. "It's probably cost-effective in men, but it's unlikely to be cost-effective in women," although the data in men is still shaky, she said.

The study didn't look at any other potential tests, such as blood tests to detect signs of inflammation, which could also help doctors more accurately estimate heart disease risk.

Researchers agreed that because of the inconclusive findings, carefully-conducted studies done in people are needed to see how cost-effective coronary calcium screening is in reality.

"All a model like this does is tell us it might be worthwhile doing, but... it still looks like it's a pretty expensive endeavor," O'Malley told Reuters Health.

Leslee Shaw, who studies risk detection at Emory University in Atlanta, said there's evidence showing that coronary calcium screening does help determine a patient's likelihood of getting heart disease. But she said it was "disappointing" that the current study didn't always find it to be cost-effective.

She said some patients may want to discuss the test with their doctors, but researchers emphasized that it's not helpful or worth the risks in all people.

"You only limit coronary calcium (screening) to people who have a few risk factors," such as high cholesterol, diabetes or a family history of heart disease, Shaw told Reuters Health. "You wouldn't just go out and massively screen everyone."